Nuclear Reaction Analysis (NRA) and X-ray fluorescence induced by PIXE (XRF-PIXE) have been developed to improve the sensitivity for the determination of low Z elements in narrow regions (around 1 mm²) of a matrix rich in high Z elements (gold, silver, copper) and especially for the understanding of brazing procedures of archaeological gold artifacts. Nuclear (d,p) reactions for the analysis of Si and S, and incidentally Mg, AL, P, Cl, K, Ca, have been carefully investigated in order to determine the most useful deuteron energy for sensitive and interference free determinations of these low Z elements. Production of characteristic X-rays by proton irradiation of a single elemental target is proposed to selectively induce fluorescence on elements of interest in such precious samples without excitation of x-ray lines of the most abundant element (gold).